Manufacture of cadmium pigment



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MUWMD'TWRE UF t fgw.,

tto mowing.

To all whomi muy concern:

Bo it known thu-t f, donn R. Mouscron., u. citizen of tho UnitedA Stntoo, iosiding ut Ciui'kduic, in tho county of Yuvupani und toto of Arizona, hoyo inyontod coito-in new und useful fmyoiovomonto in tho Monofootui'o of Cadmium Pigmont, of which tho foflowing is o opocificution.

My invontion hun foilution to iinpi'oi/o-v monto in tho munufuctnio of cwdmium pigmont, und consists in tho noi/oil foutuios' moro fufiy sot foi'th in tho spooificution und pointod ont in tho cfu/imo..

Tho objoct of tho ptooont inyontion is to utifizo tho zinc dust piocipitutos thutni'o obtnincd by ti'outing zinc oulfuto solutions with inotufiic nino, ootot foi'th in tho nnbh cutionl of John fd.. diffuus/ton on pi'oocos of purifying zincl suffuto solutions, coponding hoiowith fho zinc dust pi'ocipituto contoino finoiy diyidod motuific zinc, niotuiiic coppoi", cudmiuin und umonic.

'fho biot stop in tho p-i'ocoss is to oiiininuto tho coppoi, which is'insoilubilo in difuto suifutic unid (oucopt ut high ton'iyioi'utuno).

fn yiow of tho foot thut copioni oxidiuos irony -ousiiy by contact with uit' to coppoi" o xid, which is solubio in dilluto suifui'ic ncid, it lo t nocossuiy to trout tho tino dust ptocipituto ut onco uftoii fiiti'ntion of tho tino suffuto soiution oi' hooyoit covoiod with wuto-i'.

'fho zinc dust piociyoituto is piucod in u Y suitobio tonh oi' yoosoi und diiluto sulfuric tti titi

ncid (5% to 10%) uddod. 'fho suffuiic ucid, of couisc, immodiutofy uttucho tho Zinc, unduftoi'l nny yiofont fonction hos tuition 'piuco tho mutuio io hootod modo/iotoiy with stoom. Tho tomponutui'o to which tho mintuio is houtod shoufd bo high onough to conso tho cudminin und 4oinc to dionofyo., but not tho copioni', @houid tho zinc dust piocipituto contuin oily food., thut wiif not bo octod on by tho dihito onifuiic ucid, but wilt i'omlnin in tho tooiduo, "fho fonctions brought about by tho suffniio ooid nio us foffows:

ooiution o in o oooh/od no toffg roudily dissolved. After tho fonctions are compiotod und all tho cadmium und zinc in soiution, tho soiution is ltoi'od, lowing :i i'osiduo of motulfic coppoi und nisonic.. fn addition to zinc sulfato und cudmiuin sulfoto tho sofution muy contatinu Sinn/i1 amount of ui'sonic (probably no omonions ucid) und un oucoss of suifniic zioid.

"fho solution is now houtod in u ouitobio yossoi with u mctoiiic suid, ouch us bni'uin suifid sofution und tho foifowing i'ouctiono biought about:

The `tino sulhd loi'ociyoitutod muy hoyo tho foimufo SnSQfLU oi11 Znffz@ whiio tho cudmium sufd muy bo contominntod with Cdtt. ff uny uioonc is piiooont-it wiii bo p'iccipitutod us ASZSS.. Tho iosuit ing piocipitutc is thon woohod, diiod, andi ground topi'oduco u point pigment with u doop yoifow to oiungo coioi.

1IWhon ilithopbno is nood :is tho piocipitnting ugent instood of barium ouifid tho iro uctions one os foiiows:

'sulfid is usod otono us tho pirocipitoting ogont tho fonction would bo tho sumo oiicopt that tho inth is not piooont. A K

Tho i'osulting pigniont contnining iubm'- @dbf'nd und u sinofl omount of lie@ is yiitnuifytho sin-mo us fithoponc/in coyoiing pow/oi", but coioiod yoli'ow from tho d.

Hoving dosciibod my invontion, f cfuiirn:4

i. iiho pin-cous of monufoctui'ing cudmium pigmont from nino dust prociyi-itotos which oonsistoin tfooting tho p-iocipitotoo with dihito ouifuiic :icid to disoofvo tho Zinc, booting tho miutui'o to disoofyo tho codmium in 'tho piocipitutc, dmwing off tho s'o-fution containing cudnlium ouifnto und zinc out foto, und thofooftoo fronting tho sumo with o uniud to poocipituto tho zinc und coiuni os o'uids., I

.it 'tho piocooo of munufoctuting u con piont fiom nino dint ygodiyntutoo tpociiicution of Letton-s f'utont. Pgyfqnfggd Mgg, @y yggjtm y itpylicntion filou tugust ft, tutt. tcriul tto. tutt'ft.

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fitti imv containing metallic copper and cadmium,

` 'which consistsy in treating the` precipitate with dilute sulfuric acid to dissolve the zinc, raisin the temperature of the mixture sufficiently to dissolife the cadmium but not the copper, drawing o' the solution containi zinc sulfate and cadmium 'sulfate and treating the same with a sulfdfto precipitate the zinc and cadmium as sulfids.

3. In the manufacture of cadmium pigment, the process which consists in treating zinc dust precipitatesv containing metallic copper and cadmium with dilute sulfuric .acid to dissolve the yzinc as zinc sulfate,

thereafter heating thev mixture to a temperatureto-eect a solution of the cadmium asA cadmium sulfate, drawing oil' they solution and thereafter treating the same with barium sulfid to precipitate the zinc and cadium as sulf and produce a paint pigment. A

4. In the manufacture of cadmium pigment, the process which consists in placing in a treatment tank zinc dust precipitates containing metallic copper, cadmium, and

arsenic, treating theprecipltate with dilutey sulfuric acid to dissolve the zinc as zinc sulfate, thereafter raising the temperature of the mixture sufficiently to dissolve the cadmium but not the copper, filtering the solution into a second treatment tank and treating the same with barium sulfid to p1recipitate the zinc and cadium as sulfids together with barium sulfate, and fin-ally Washing, drying and grinding the precipitate to produce a paint pigment.

5. In the manufacture of cadmium pigment, the process which consists in treating zinc dust precipitate containing metallic copper and cadmium with dilute sulfuric acid to dissolve the zinc and;v cadmium as sul-v fates, the mixture being heated with steam toa temperature below that at which the' copper dlssolves, drawing off the solution and thereafter treating the same with barium sulfid for precipitating the zinc and cadmium as sulids, and finally drying and grinding the precipitate to produce a cadmium paint plgment.

In testimony whereof I hereunto aix my signature.

. JOHN R. MARSTON. 

